221720070 has 64 divisors (see below), whose sum is σ = 625169664. Its totient is φ = 49614720.

The previous prime is 221720047. The next prime is 221720089. The reversal of 221720070 is 70027122.

221720070 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21552 + ... + 30131.

It is an arithmetic number, because the mean of its divisors is an integer number (9768276).

Almost surely, 2^221720070 is an apocalyptic number.

221720070 is an abundant number, since it is smaller than the sum of its proper divisors (403449594).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221720070 is a wasteful number, since it uses less digits than its factorization.

221720070 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51717.

The product of its (nonzero) digits is 392, while the sum is 21.

The square root of 221720070 is about 14890.2676268763. The cubic root of 221720070 is about 605.2502846239.

Adding to 221720070 its reverse (70027122), we get a palindrome (291747192).

The spelling of 221720070 in words is "two hundred twenty-one million, seven hundred twenty thousand, seventy".